.container {
  width: 300px;
  height: 300px;
  background-color: cyan;
}
.container .center {
  width: 200px;
  height: 200px;
  background-color: red;
}
.container .center .inner {
  width: 100px;
  height: 100px;
  background-color: greenyellow;
}
.box {
  width: 100px;
  height: 100px;
  background: purple;
}
.box:hover {
  background-color: pink;
}
